I want a dock so that I can set up tasker profile for different cases, just like day dream, to show when is docked, but not show when its charging.

I bought the "dock" that you link to. It is advertised as a docking station but when I got it it clearly says "charging cradle". I paid $25 for an $8 desktop charger. I already had a "cradle charger" at work. When I plug in my phone at work it just displays the desktop, which is what I want. My plan was to have a bedside "dock" with "daydream" enabled, with a very dim night time alarm clock. In "settings", "display", "daydream" I wanted to set "when to daydream" to "while docked". This is the big advantage of having an actual "docking charger" besides just a "charger".

About OP, I know from other phones that some configuration in the microUSB pins trigger the dock mode as well as car mode, but first of all the OS has to have it implemented. Some HTC, by example my old HTC one S, have a car mode which is triggered by both official car cradle and a special homemade microUSB with pins differently mapped.
About docks, only ones I know are philips fidelio, great options

I don't believe the Nexus 5 supports a "dock" mode at all. I've tried using a car mount(iBolt) that is built with the pin connection to trigger dock mode that worked with a HTC Evo LTE but with the Nexus it's just a charger. Had to re-write some of my Tasker profiles to get things working correctly again.

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